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Identification of Arabidopsis subtilisin‐like serine protease specifically expressed in root stele by gene trapping
Author(s) -
Kuroha Takeshi,
Okuda Asako,
Arai Masahiro,
Komatsu Yuta,
Sato Shusei,
Kato Tomohiko,
Tabata Satoshi,
Satoh Shinobu
Publication year - 2009
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2009.01281.x
Subject(s) - stele , xylem , arabidopsis , root hair , arabidopsis thaliana , apoplast , biology , methyl jasmonate , botany , lateral root , gene , root cap , shoot , meristem , mutant , biochemistry , cell wall
Xylem plays a role not only in the transport of water and nutrients but also in the regulation of growth and development through the transport of biologically active substances. In addition to mineral salts, xylem sap contains hormones, organic nutrients and proteins. However, the physiological functions of most of those substances remain unclear. To explore genes involved in xylem sap production, we identified Arabidopsis genes expressed in the root stele of the root hair zone from gene‐trap lines by randomly inserting the β‐glucuronidase gene into the genome. Among 26 000 gene‐trap lines, we found that 10 lines had β‐glucuronidase (GUS) staining predominantly in the root stele of the root hair zone and no GUS staining in the shoots. Of these 10 lines, 2 lines showed that gene‐trap tags inserted into the promoter region of the same gene, denoted Arabidopsis thaliana subtilase 4.12( AtSBT4.12 ). Analysis of AtSBT4.12 promoter using an pAtSBT4.12 ::β‐glucuronidase transgenic line showed that the AtSBT4.12 gene was expressed only in the root stele of the root hair zone. AtSBT4.12 expression in roots was increased by application of methyl jasmonate. Subtilase proteins are commonly detected in proteomic analyses of xylem sap from various plant species, including Brassica napus , a relative of Arabidopsis . These results suggest that AtSBT4.12 may be a protein localized in the apoplast of root stele including xylem vessel and involved in stress responses in Arabidopsis roots.